The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1887-05-14
Correspondence Baltimore County Union.
SnTENTTFIC MISCEII.ANY


MOVEMENT OF THE AIR.
The mean atmospheric pressure for the whole
earth, as shown by the barometer, is found by
Kleber of st. Petersburg, to be 2991 inches. That
for the northern hemisphere is 1896 inches, and
for the southern 29.77. The average northern
excess is greatly increased in January, but be-
comes deficiency in July, when the southern
pressure is slightly the greater, mass OF air suf.
fcient to give a pressure of nearly "a over
hemisphere appearing to be periodically shifted
from one side of the equator of the other by the
changing seasons.
THE WORLDS CLOUDS.
In a paper before the Meteorological Society of
London, the Hon. R. Abercromby has shown that
cumulus is the commonest form of clouds in the
tropics cumulo-stratus and cirrostratus in the
Arctic regions. Although the forms alike, the
prognostic value of and shape is not the same
everywhere, woolly clouds denoting fine weather
in England and rain in Italy.
METEoRIc THUNDER.
The most rapid cannonshots, according to M.
Him, scarcely reach speed of 1000 feet per
second, while meteorites penetrate the air at the
rate of 25 or 80 miles, and even more, per second.
With this velocity, the air is at once raised to
temperature of 1000 to 10000 degrees, and the
meteorites surface is torn away by atmospheric
friction and vaporized by the heat. The sounds
produced range from the whistling of bullet to
the crash and roll of thunder. They are explained
by this author resulting from the rush of air to
ill the gap in the rather than from actual
explosion, being analogous to thunder after light
ming.
THE NEW AsTRoLoGY.
In the new Photographic instruments OF the
Brothers Henry, at the Paris Observatory, the
sensitive plate is placed in the exact chemical
focus of the telescope, and given three exposures
to the region of the heavens to be posures so very
slightly, however, that the impressions of each
star appear as one a magnifer being necessary
to reveal the triple nature of the dots. This
plan makes the stellar images distnguishable
from spots ON the plate, and has unexpectedly
shown other advantages. Thus, tor the same time
the triple exposures record much fainter stars, as
three invisible images may unite in visible one !;
while small planets quickly detected among
the fixed stars by the irregularity in the triangle
which their motion is sufficient to produce even
during an exposure of fifteen minutes. The pro-
duction of these pictures is very trying work, and
wonderful patience and skill are required to keep
the instrument for three consecutive hours, with
out moments relapse, vigorously pointed TO-
ward one spot in the sky.
FISHES OUT OF WATER.
There are several species of fish which are
much more at home out of their natural element
than any specimens of the human race are IN
water. The climbing perch (Ana6as seandens)
is a remarkable example found in Asia. Thls
singular creature appears much like other perch,
but is endowed with extraordinary power OF
leaving failing streams, climbing the banks, and
proceeding over dry land in quest of better-hlled
water-courses. Hundreds of them have been seen
at distance of fifty or sixty yards from pool
Just abandoned, and they were still travelling,
though the ground was rough that this distance
must have required sufficient muscular exeruon
to take them half mile over level ground. Some
writers even assert that this fish is capable OF
climbing the rough stems of palm-trees. The
fisherman of the Ganges, who subsists largely on
climbing perch, are accustomed to keep them in
dry earthern pans for five or six days after catch
ing, and they live this strange life without ap-
parent discomfort.
AN ASTRONOMICAL PUZZLE.
The curious "canals' on the surface of Mars are
like nothing else known, and still remain uneX-
planned. They are seen as nearly straight lines,
and appear like cuttings with parallel sides, ex-
tending from sea to sea across the planets con-
tinents. They are about fifteen miles wide. They
were discovered few years ago by Schiaparelll,
an italian astronomer, and their existence has
since been confirmed by several other observers.
MISCELLANEOUS.
Steatite has been recommended as dentrlhce
by M. Paul Vigier, who has discovered that 1t
prevents the formation of tartar. His tooth pow
der contains powdered steatite (soapstone), 60
grammes; dried alum cream of tartar, gram
mes powdered cochineal, 10 grammes; essence
of peppermint or other perfume, 20 drops.
A scientific novelty is a lens which magnlhes,
yet is perfectly fat on both sides. 1t is made at
jena by the manufacturers of Prof. Abbe's new
optical glass. The lens consists of single disc
whose density varies SO that its refr.Os. power
decreases ros-I--ly fram the surface inward.
Queen Victoria's jubilee year Is also that OF
teegraphy, the first patent for an electric teie-
graph having been issued June 20, 1871 week
before the Queens accesson-to Cooke and Wheat
stone. British electricians propose to celebrate
with an exhibition illustrating the development
of telegraphy and telephony.
In study of pigs, the American Consul at
Copenhagen has added thirty pounds to the weight
of some animals by having them daily washed.
Besides cleanliness, easily masticated food gave
striking results. When whole corn is fed them,
only half of it is available food, the other hall
passing away in an undigested form.
Spectroscopic observations give different com
position for variable stars at different PERIODS
thus indicating that the variability results from
the combustion of different substances.
A material called "featherbone," prepared from
the quils of geese and turkeys said to be largely
taking the place of whalebone for many purposes;
The London Society of Arts offers two gold ana q
four silver medals for the best electric hgn'